Punch-press die



Sept. A24, 1929.

v H. PHILIP PUNCH PRESS DIE Filed March 14, 1927 2 Sheets-Sheet l Sept.24, 1929. H PHlLlP 1,729,123

PUNCH PRESS DIE Filed March 14. 1927 2 sheets-sheet '2 Patented Sept.24,' 1929 PATENT OFFICE HOWARD PHILIP, OF NORTH CHICAGO, ILLINOIS,ASSIGNOR TO FANSTEEL PRODUCTS COMPANY, INCL, OF NORTH CHICAGO, ILLINOIS,A CORPORATION F NEW YORK i rUNcH-raass nm Application Med Iarch 14,1927. Serial No. 175,837.

-My invention relates to an improved die for use in punch pressesadapted' to make thin metal stampings, and relates especially to ameansfor stacking thestampings whereby they may be easily handled.

Heretofore in stamping processes 1t has been desirable to stack thestampings in a suitable guide s'othat they may be removed in largenumbers and packed without the 1o necessity of sorting. No diiiculty isexperienced when the stamping is cut on substantially all sides.

However, when only a small edge of the stamping-is cut by the die and alarge portion of the edge fits loosely7 in the aperture of the die, ithas been found that the stampings are not held in place by friction withthe sides of the die, and the resiliency of the stack of stampings inlthis guide forces the thin stampingsl on top in an upward direction, sothatthey tend to follow the punch andto v'fall out on top of the die.

This ditliculty has "made it impossible to use a guide for collectingthe stampings. Instead a large box has been placed under the press andthe stampings have been allowed to fall in this box. This required someten or fifteen sorters to arrange the blanks in order.

improved die with means for preventing this.

upward movement of the stampings whereby a guide may be used forcollecting the stampings.

Other objects will be apparent as the description oi the inventionproceeds.l In the accompanying drawings which'represent a preferredembodiment of my invention and in which similar reference charactersrefer to likewparts,

Fig. 1' represents a conventional punch press;

Fig. 2 is a plan of the improved die;

` on lines 3-3 of Fig. 2;

lig. 4 is a detail view f the serrated dog; an y 'Fig 5 is tHe plan 'ofthe thin-metal sheet from which the stampings are made.

The conventional punch press shown in 27 adapted to receive the pilotpin 20 for the Fig. 3 is a section of the improved die takenl inaperture 34 and which is threaded to re- Fig. 1 may be briefly describedas a suitable `base 10 supporting a frame 11 and a die 12.-

Frame 11 carries a suitable pulley 13-which is mounted on a shaft 14rotatable in suitable bearings 15. The pulley 13 may be driven by anysuitable power means, not shown.

Secured to the shaft 14 is a cam 16 which4 operates a suitable presshead 17 slidably mounted in the frame 11, On the underside of the presshead are suitably mounted punches 18 and 19 and a pilot pin 20, thepurpose and construction of which elements are well known and need nofurther description.

. In the preferred embodiment the strip of metal21 to be stamped isautomatically fed over roller 22, the driving means and the strip feedbeing properly synchronized. A pedal 23 may operate a clutch fordisengaging the driving mechanism or regulating the speed of themachine.y

The die12 is shown in detail in Figs. 2 and 3. This particular die isused for stamping out L-shaped pieces of thin coated iron to be used informing laminated cores for alternating current transformers. The diemay be described as a steel block having apertures 24 and 25. l Thestrip is fed from left to right over this die. and to prevent the edgeof thejstrip from hitting against the right hand side of' aperture 24 aslight depression 26 is made. as shown in Fig. 2, allowing the strip toslide easily past the first opening.

The second aperture 25 includes a channel purpose cf aligning the work.Aperture 25 also includes channels 28 and 29 in which are slidablymounted serrated dogs 30.

,These serrated dogsv may be described as a smallblock-provided with acam face 31 and a series of teeth 32, the purpose of which will behereinafter described. Each `dog is secured to a. rod 33 which isslidably mounted ceive a nut- 35 at its outer end, as shown in 95 Figs.2 and 3.

The dogvand the die are also provided with Aaligned openings 36 and 37in which there is a compressed spring 38 which tends to forcef the dog30 toward the aperture. The die is 109 ings due to the resiliency of thecolumn oi.v

provided with suitable screws and fastening means which are well knownin the 'art and need no description here.

Fig.` 5 represents a thin stri of iron from which the stampings aremace. It will be noted `that the entire blank is utilized with theexception of a small margin c and c.

When the strip is fed throughthe press.`

punch 19 cut-s out stampings a., and punch 18 cuts off stampings b.There is always one stamping b between punch 18 and punch 19. Forinstance, while punch 18 is cutting stamp,- ing opsrhn, punch 19 will becutting strip mg/vg/ 1's. Immediately precedingl the punchino' operationthe pilot pin 20 will engage sidbes 'mit and 81 to align the stripproperly.

rI he operation of my invention may be described as follows:

Ineach operation 'punch 19 cuts strip a alongall of the edges with theexception of a small portion z/y. Therefore, the strips a frictionallyengage the sides of the aperture with sufiicient force to preventanyupward movement of these stampings. There is a Very strong vupwardthrust of kthese stampstrips in guide 40, but the frictional engagementwith the side walls is suicient to overcome this upward force.

However, the stampings I) in the second aperture 25 are only cut alongedges on and um. The edges mlwspo are pressed loosely in the die, butare not cut in this process. These edges do not bear against the sideswith suicient pressure to hold them in place, and the tendency is forthe column of strips 39 in the guide 41 to follow the upward movement ofpunch `18 and fall out of or obstruct the die.

` Heretofore, as above stated, it has been deemed impossible to use aguide for stacking and collecting stampingsb and a large vlwooden boxwas placed under the aperture 25, in which the stalnpings were allowedto fall indiscriminately', and a large amount of time and labor wasrequired to sort out and stack the stampings.

Thev operation of the serrated dog 30 makes it possible to use a guidefor collecting these stampings. When the punch 18 descends its edgeimpinges on the cam surface 28 of the serrated dog, which causes it toslide back against the compressed spring 38 and allow the punch with.the stamping to descend. On the upward movement, however, theserrations or Vteeth 32 positively engage the stampings and prevent theupward movement thereof. These teeth or serrations are preferably in agradual step down relation, that is, each tooth is set in a slightamount further than `the tooth above it. Withftlie use of this improveddevice, no diiiiculty is experienced in stacking the stampings, eventhough a very small fraction ofthe perimeter of the blank is cut by thedie.

While I have described a specific example of my invention, it isunderstood that I am not limited tov the details i shown and described,except as defined by the .following in operative position.

2. A stamping die provided with a cutting edge and a non-cutting edgesurrounding an aperture and a channel in one side of the aperture, aserrated dog in said'channel and means to urge said dog toward theaperture.

ture, a vertical channel communicating with said aperture and ahorizontal bore commu'- nicating with said channeha rod slidably mountedin said bore, a serrated dog slidably 3. A die provided with a verticalaper-'l mounted in said channel and fixed to said' rod,

and reslientmeans urging said dog toward said aperture.

4. Means for stacking thin stampings where the frictional engagementwith the sides of the die do not hold said stampi'ngs in place whichcomprises a slidably mounted serrated dog, the serrated portionextending normally in the path of a punch, a cam face on said dogwhereby the descending punch forces back the dog, and resilient meansurging the dog forward into operative position; i

5. In a punch press, a punch, a stamping die provided with an aperturetherethrough, a guide .for stampings associated with said die andcommunicating with 'the aperture therein whereby stampings may be forcedthrough the die by the punch and stacked in the guide, and meansassociated with the die. for compensating for any lack of frictionbetween the stampings and the die, thereby preventing the upward forceof the stack of stampings from pushing the top stampings yout of theaperture in the'die and extending Withinl the die aperture.

6. In combination a stamping die provided with an aperture ,having acutting edge.

and a non-cutting edge, and a retaining dog in saidaperture at saidnon-cutting edge, said dog comprising a block provided with a recedingseries vof ratchet teeth and with a cam surface above the top tooth.

In witnesswhereof, I hereuntosubseribe my name this 8 day of March,1927.

. HOWARD PHILIP.

